Device for increasing the life of dies for wire drawing frames



May 4, 1965 M. EH|N 3,181,325

DEVICE FOR INCREASING THE LIFE OF DIES FOR WIRE DRAWING FRAMES Filed Aug. 28, 1961 INVENTOR.

3 I M/m/o (farm/v f: JM W AITTW United States Patent 3,181,325 DEVICE FOR INCREASING THE LIFE OF DIES FOR WIRE DRAWING FRAMES Mario Cecchin, Via Stabilini 14, Malgrate, Lecco, Italy Filed Aug. 28, 1961, Ser. No. 134,328 Claims priority, application Italy, Dec. 31, 1960, 22,525/60, Patent 645,763 4 Claims. (Cl. 72-43) It is a known fact that wire-drawing or similar dies are subject to considerable wear because of which they must frequently be reamed or cut (rebored). After a certain number of reaming operations the dies are no longer use ful and must be replaced with others which operate efiiciently.

The wear produced usually takes the form of a ringshaped groove which becomes very pronounced after a few hours in continuous operation, making the job of removing this groove very laborious and requiring frequent rereaming.

This invention relates to a procedure and a device which make it possible to appreciably increase the life of the die or the time required between one reaming operation and the next and, furthermore, enables the lubricant located adjacent and in front of the die to be distributed more evenly and absolutely prevents scoring of the die, even after long, continuous use.

The procedure is characterized by the fact that the wire or other similar material to be drawn, instead of being fed into the die straight along the axis of the hole in the die, is fed in obliquely, at an angle, being made to rotate about the axis of the die hole, forming a double coneshaped envelope by the path through which it travels, so that the wear on the die will be distributed more evenly over a broader area instead of being localized to form a ring-shaped groove.

The device embodying the invention, making it possible to carry out the procedure is characterized by the fact that a rotating arm or equivalent member, provided with an eye or hole, oblique or off" center with respect to the axis of the die and provided for the passage of the wire or the like, is located ahead of the die hole. This rotating arm or equivalent member is held, preferably, inside the lubricating box, wherein the arm is so placed that its rotation during the drawing of the wire causes the wire to describe a double cone in the path through which it travels. The double cone diverges over its length between the point where it leaves the sheave and the eye or eccentric hole and converges over its length between the latter point and the die hole.

The accompanying drawing shows a non-restrictive form of embodiment of the invention in one of its preferred forms.

FIG. 1 is a vertical, longitudinal section taken through the axis of the die.

FIG. 2 is a sectional drawing of a die showing the ringshaped groove worn in the die, such as occurs when using normal or conventional drawing methods.

FIG. 3 is a sectional drawing of a die showing the broader area of Wear occurring using the process described in this invention.

In reference to FIG. 1, the device comprises the lubricating box 1, carrying the die 2, through the hole 3 of which passes the Wire 4 to be drawn, coming from point A and traveling in the direction indicated by arrow 5.

An important characteristic of the device is comprised by cylinder 6 with an oblique feed hole 15, at a point off center with respect to the axis 7 of the die hole, said hole 15 being able to revolve about axis 7 in the direction indicated by arrow 8.

The rotation of cylindrical arm 6 is produced by the 3,181,325 Patented May 4, 1965 ice following mechanism: by sheave 9 about which the wire (4 and 4) is partially wrapped, transmitting the motion through drive 10 to worm gear 11 which meshes with helical gear 12. Cylinder 6 is supported by bearings 13 and 13 and carries at its opposite end the arm 16. Cylindrical arm 6 has a feed hole 15 and an eye 15 through which wire 4 passes before entering die 2.

Arm 16, which carries sheave 9 can be rotated downwards through to a position as shown by broken lines in FIG. 1, so that it can be adapted to the position of the wire, depending on whether the wire arrives from above or from below.

The device operates as follows: when the wire 4 and 4 starts its motion through the die, sheave 9, upon turning, sets worm gear 11 in motion, along with helical gear 12 and, as a result, cylinder 6. The wire 4, before entering die hole 3 of die 2 thus describes a double conical envelope, diverging over its length A-B, C and converging over its length B, CD. This rotation causes an appreciable decrease in the depth of the ring-shaped groove 19 caused by wear in the die (see FIG. 2), distributing the wear over a broader area I of 20, shown in FIG. 3.

In normal or conventional drawing heads (FIG. 2) in which the wire arrives straight along the axis of the die hole 3, the end 4" of the Wire which comes temporarily in contact with the tapered wall which precedes the hole digs a groove 19 in said wall which is deep and limited to a restricted area and which makes it necessary to ream out an appreciable thickness of material from the die, to make the die operate eifectively.

In the case shown in FIG. 3, the oblique or angular feed at of the wire to the die and rotation of the wire to describe the conical or tapered path 5 through which it travels, causes the wear to be distributed over a surface I of 20 which is much broader and thus of lesser thickness, so that the reaming operation carried out on the die need only be done after a period of time much longer than in the case as shown in FIG. 2. For example, it may be said that while using conventional methods the die must be reamed out after eight hours of continuous use, the use of the device and procedure described in this invention will make it possible to operate the die continuously for from 24 to 32 hours, before reaming becomes necessary, with the same amount of die material being reamed out as in the case using the conventional feed method.

It should also be noted that the lubricant which is provided in area 23 (FIG. 2) will be better distributed using the procedure described in this invention, since the wire, itself, helps to distribute the lubricant on the tapered surface which immediately precedes the die hole. This point is also an important factor in reducing the wear on the die and makes the operation of the die smoother.

Naturally the means used to rotate the Wire as described herein may also be different, without, however, falling outside the scope and coverage of the appended claims.

What I claim is:

1. A drawing device which may be applied to wire drawing machines in order to increase the life of their dies and to prevent the formation of any ring-shaped grooves in the die apertures, said drawing device comprising a lubricating box, a wire-drawing die mounted within said box, said die having an aperture therein through which the wire being drawn is passed, a rotatable member disposed ahead of the die along the axis of the die aperture, a wire-guiding eye carried by said rotatable member at a point thereon which is off-center with respect to said axis, a sheave mounted tangentially to said axis and engaging said wire, means for angularly adjusting the operating position of said sheave about said axis in accordance with the direction of approach of said wire to the drawing device, and means operatively connected to said sheave for driving said rotatable member in rotation in response to the movement imparted to the sheave by the wire being down, the resulting circular motion of said wire-guiding eye about said axis causing the wire to follow a first path segment comprising a divergent conical envelope between the sheave and the eye and then to follow a second path segment comprising a convergent conical envelope which converges at said die aperture.

2. A drawing device according to claim 1, wherein the means for driving said rotatable member in rotation comprises a worm gear, means for transmitting the sheave motion to said worm gear, and a helical gear connected to said rotatable member and engaged with said Worm gear, the axis of said helical gear being coincident with the axis of said die aperture, said helical gear causing said rotatable member carrying the wire-guiding eye to rotate.

3. A drawing device according to claim 1, wherein the sheave position adjusting means comprises a stationary, curved arm mounted upon said box so as to be selectively movable through at least 180 of rotation to allow the 'wire to arrive at the sheave from either above or below .the drawing device.

4. A wire drawing apapratus for increasing the life of the die incorporated therein, comprising a die includ- 25 ing a hole receiving the wire being drawn, support means rotatable about the axis of said hole, wire guiding means mounted in said support means for rotating said wire around a path forming a conic envelope with divergent and convergent sections in the region preceding said hole, sheave means engaging said wire for directing it obliquely to said guiding means from any desired direction of approach by the wire into the wire drawing apparatus, said sheave means being rotated by the wire being drawn, and transmission means driven by said sheave means for driving said support means in rotation.

References Cited by the Examiner UNITED STATES PATENTS 960,016 5/10 Horton 20516 2,329,376 9/43 Illmer et al 205-21 2,349,104 5/44 Morgan 205-16 2,360,104 10/44 Symmes 205-16 2,400,866 5/46 Kronwall 205-21 3,029,845 4/62 Egedal 140l47 FOREIGN PATENTS 466,516 3/13 France.

CHARLES W. LANHAM, Primary Examiner.

V/ILLIAM W. DYER, JR., Examiner. 

1. A DRAWING DEVICE WHICH MAY BE APPLIED TO WIRE DRAWING MACHINES IN ORDER TO INCREASE THE LIFE OF THEIR DIES AND TO PREVENT THE FORMATION OF ANY RING-SHAPED GROOVES IN THE DIE APERTURES, SAID DRAWING DEVICE COMPRISING A LUBRICATING BOX, A WIRE-DRAWING DIE MOUNTED WITHIN SAID BOX, SAID DIE HAVING AN APERTURE THEREIN THROUGH WHICH THE WIRE BEING DRAWN IS PASSED, A ROTATABLE MEMBER DISPOSED AHEAD OF THE DIE ALONG THE AXIS OF THE DIE APERTURE, A WIRE-GUIDING EYE CARRIED BY SAID ROTATABLE MEMBER AT A POINT THEREON WHICH IS OFF-CENTER WITH RESPECT TO SAID AXIS, A SHEAVE MOUNTED TANGENTIALLY TO SAID AXIS AND ENGAGING SAID WIRE, MEANS FOR ANGULARLY ADJUSTING THE OPERATING POSITION OF SAID SHEAVE ABOUT SAID AXIS IN ACCORDANCE WITH THE DIRECTION OF APPROACH OF SAID WIRE TO THE DRAWING DEVICE, AND MEANS OPERATIVELY CONNECTED TO SAID SHEAVE FOR DRIVING SAID ROTATABLE MEMBER IN ROTATION IN RESPONSE TO THE MOVEMENT IMPARTED TO THE SHEAVE BY THE WIRE BEING DOWN, THE RESULTING CIRCULAR MOTION OF SAID WIRE-GUIDING EYE ABOUT SAID AXIS CAUSING THE WIRE TO FOLLOW A FIRST PATH SEGMENT COMPRISING A DIVERGENT CONICAL ENVELOPE BETWEEN THE SHEAVE AND THE EYE AND THEN TO FOLLOW A SECOND PATH SEGMENT COMPRISING A CONVERGENT CONICAL ENVELOPE WHICH CONVERGES AT SAID DIE APERTURE. 